// des.c : Data Encryption Standard
// 2013.3.22 v1.2

#include "3des.h"

//初始置换表IP
static int IP_Table[64] = {  57,49,41,33,25,17,9,1,   
                     59,51,43,35,27,19,11,3,   
                     61,53,45,37,29,21,13,5,   
                     63,55,47,39,31,23,15,7,   
                     56,48,40,32,24,16,8,0,   
                     58,50,42,34,26,18,10,2,   
                     60,52,44,36,28,20,12,4,   
                     62,54,46,38,30,22,14,6};  

//逆初始置换表IP^-1 
static int IP_1_Table[64] = {39,7,47,15,55,23,63,31,   
                       38,6,46,14,54,22,62,30,   
                       37,5,45,13,53,21,61,29,   
                       36,4,44,12,52,20,60,28,   
                       35,3,43,11,51,19,59,27,   
                       34,2,42,10,50,18,58,26,   
                       33,1,41,9,49,17,57,25,   
                       32,0,40,8,48,16,56,24}; 

//扩充置换表E  
static int E_Table[48] = {31, 0, 1, 2, 3, 4,   
                  3,  4, 5, 6, 7, 8,   
                  7,  8,9,10,11,12,   
                  11,12,13,14,15,16,   
                  15,16,17,18,19,20,   
                  19,20,21,22,23,24,   
                  23,24,25,26,27,28,   
                  27,28,29,30,31, 0};   
  
//置换函数P  
static int P_Table[32] = {15,6,19,20,28,11,27,16,   
                  0,14,22,25,4,17,30,9,   
                  1,7,23,13,31,26,2,8,   
                  18,12,29,5,21,10,3,24};   
  
//S盒     
static int S[8][4][16] =//S1   
            {{{14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7},   
              {0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8},   
                {4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0},   
                {15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13}},   
                //S2   
              {{15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10},   
              {3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5},   
              {0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15},   
              {13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9}},   
              //S3   
              {{10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8},   
              {13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1},   
                {13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7},   
              {1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12}},   
              //S4   
              {{7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15},   
              {13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9},   
              {10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4},   
              {3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14}},   
              //S5   
              {{2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9},   
              {14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6},   
              {4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14},   
              {11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3}},   
              //S6   
              {{12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11},   
              {10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8},   
              {9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6},   
              {4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13}},   
              //S7   
              {{4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1},   
              {13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6},   
              {1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2},   
              {6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12}},   
              //S8   
              {{13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7},   
              {1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2},   
              {7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8},   
              {2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11}}};

//置换选择1               
static int PC_1[56] = {56,48,40,32,24,16,8,   
              0,57,49,41,33,25,17,   
              9,1,58,50,42,34,26,   
              18,10,2,59,51,43,35,   
              62,54,46,38,30,22,14,   
              6,61,53,45,37,29,21,   
              13,5,60,52,44,36,28,   
              20,12,4,27,19,11,3};   
  
//置换选择2 
static int PC_2[48] = {13,16,10,23,0,4,2,27,   
              14,5,20,9,22,18,11,3,   
              25,7,15,6,26,19,12,1,   
              40,51,30,36,46,54,29,39,   
              50,44,32,46,43,48,38,55,   
              33,52,45,41,49,35,28,31};

//左移次数规定   
static int MOVE_TIMES[16] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};

static int ByteToBit(ElemType ch,ElemType bit[8]);//字节转换成二进制  
static int BitToByte(ElemType bit[8],ElemType *ch);//二进制转换成字节 
static int Char8ToBit64(ElemType ch[8],ElemType bit[64]);//将长度为8的字符串转为二进制位串  
static int Bit64ToChar8(ElemType bit[64],ElemType ch[8]);//将二进制位串转为长度为8的字符串  
static int DES_MakeSubKeys(ElemType key[64],ElemType subKeys[16][48]);//生成子密钥  
static int DES_PC1_Transform(ElemType key[64], ElemType tempbts[56]);//密钥置换1
static int DES_PC2_Transform(ElemType key[56], ElemType tempbts[48]);//密钥置换2
static int DES_ROL(ElemType data[56], int time);//循环左移
static int DES_IP_Transform(ElemType data[64]);//IP置换   
static int DES_IP_1_Transform(ElemType data[64]);//IP逆置换  
static int DES_E_Transform(ElemType data[48]);//扩展置换 
static int DES_P_Transform(ElemType data[32]);//P置换  
static int DES_SBOX(ElemType data[48]);//S盒置换   
static int DES_XOR(ElemType R[48], ElemType L[48],int count);//异或 
static int DES_Swap(ElemType left[32],ElemType right[32]);//交换
static int DES_EncryptBlock(ElemType plainBlock[8], ElemType subKeys[16][48], ElemType cipherBlock[8]);//加密单个分组   
static int DES_DecryptBlock(ElemType cipherBlock[8], ElemType subKeys[16][48], ElemType plainBlock[8]);//解密单个分组

//字节转换成二进制  
static int ByteToBit(ElemType ch, ElemType bit[8]){   
    int cnt;   
    for(cnt = 0;cnt < 8; cnt++){   
        *(bit+cnt) = (ch>>cnt)&1;   
    }   
    return 0;   
}   
  
//二进制转换成字节 
static int BitToByte(ElemType bit[8],ElemType *ch){   
    int cnt;   
    for(cnt = 0;cnt < 8; cnt++){   
        *ch |= *(bit + cnt)<<cnt;   
    }   
    return 0;   
}   

//将长度为8的字符串转为二进制位串   
static int Char8ToBit64(ElemType ch[8],ElemType bit[64]){   
    int cnt;   
    for(cnt = 0; cnt < 8; cnt++){           
        ByteToBit(*(ch+cnt),bit+(cnt<<3));   
    }   
    return 0;   
}   
  
//将二进制位串转为长度为8的字符串    
static int Bit64ToChar8(ElemType bit[64],ElemType ch[8]){   
    int cnt;   
    memset(ch,0,8);   
    for(cnt = 0; cnt < 8; cnt++){   
        BitToByte(bit+(cnt<<3),ch+cnt);   
    }   
    return 0;   
}   
 
//生成子密钥      
static int DES_MakeSubKeys(ElemType key[64],ElemType subKeys[16][48]){   
    ElemType temp[56];   
    int cnt;   
    DES_PC1_Transform(key,temp);//PC1置换   
    for(cnt = 0; cnt < ROUND; cnt++){//16轮跌代，产生16个子密钥   
        DES_ROL(temp,MOVE_TIMES[cnt]);//循环左移   
        DES_PC2_Transform(temp,subKeys[cnt]);//PC2置换，产生子密钥     
    }   
    return 0;   
}   
   
//密钥置换1
static int DES_PC1_Transform(ElemType key[64], ElemType tempbts[56]){   
    int cnt;       
    for(cnt = 0; cnt < 56; cnt++){   
        tempbts[cnt] = key[PC_1[cnt]];   
    }   
    return 0;   
}   

//密钥置换2     
static int DES_PC2_Transform(ElemType key[56], ElemType tempbts[48]){   
    int cnt;   
    for(cnt = 0; cnt < 48; cnt++){   
        tempbts[cnt] = key[PC_2[cnt]];   
    }   
    return 0;   
}   

//循环左移     
static int DES_ROL(ElemType data[56], int time){      
    ElemType temp[56];   
    //保存将要循环移动到右边的位  
    memcpy(temp,data,time);   
    memcpy(temp+time,data+28,time);   
    //前28位移动      
    memcpy(data,data+time,28-time);   
    memcpy(data+28-time,temp,time);   
    //后28位移动   
    memcpy(data+28,data+28+time,28-time);   
    memcpy(data+56-time,temp+time,time);       
  
    return 0;   
}   

//IP置换
static int DES_IP_Transform(ElemType data[64]){   
    int cnt;   
    ElemType temp[64];   
    for(cnt = 0; cnt < 64; cnt++){   
        temp[cnt] = data[IP_Table[cnt]];   
    }   
    memcpy(data,temp,64);   
    return 0;   
}   

//IP逆置换    
static int DES_IP_1_Transform(ElemType data[64]){   
    int cnt;   
    ElemType temp[64];   
    for(cnt = 0; cnt < 64; cnt++){   
        temp[cnt] = data[IP_1_Table[cnt]];   
    }   
    memcpy(data,temp,64);   
    return 0;   
}   
 
//扩展置换   
static int DES_E_Transform(ElemType data[48]){   
    int cnt;   
    ElemType temp[48];   
    for(cnt = 0; cnt < 48; cnt++){   
        temp[cnt] = data[E_Table[cnt]];   
    }      
    memcpy(data,temp,48);   
    return 0;   
}   

//P置换   
static int DES_P_Transform(ElemType data[32]){   
    int cnt;   
    ElemType temp[32];   
    for(cnt = 0; cnt < 32; cnt++){   
        temp[cnt] = data[P_Table[cnt]];   
    }      
    memcpy(data,temp,32);   
    return 0;   
}   

//异或  
static int DES_XOR(ElemType R[48], ElemType L[48] ,int count){   
    int cnt;   
    for(cnt = 0; cnt < count; cnt++){   
        R[cnt] ^= L[cnt];   
    }   
    return 0;   
}   

//S盒置换     
static int DES_SBOX(ElemType data[48]){   
    int cnt;   
    int line,row,output;   
    int cur1,cur2;   
    for(cnt = 0; cnt < 8; cnt++){   
        cur1 = cnt*6;   
        cur2 = cnt<<2;   
        //计算在S盒中的行与列   
        line = (data[cur1]<<1) + data[cur1+5];   
        row = (data[cur1+1]<<3) + (data[cur1+2]<<2)   
            + (data[cur1+3]<<1) + data[cur1+4];   
        output = S[cnt][line][row];   
        //化为2进制   
        data[cur2] = (output&0X08)>>3;   
        data[cur2+1] = (output&0X04)>>2;   
        data[cur2+2] = (output&0X02)>>1;   
        data[cur2+3] = output&0x01;   
    }      
    return 0;   
}   

//交换  
static int DES_Swap(ElemType left[32], ElemType right[32]){   
    ElemType temp[32];   
    memcpy(temp,left,32);      
    memcpy(left,right,32);     
    memcpy(right,temp,32);   
    return 0;   
}   

//加密单个分组
static int DES_EncryptBlock(ElemType plainBlock[8], ElemType subKeys[16][48], ElemType cipherBlock[8]){   
    ElemType plainBits[64];   
    ElemType copyRight[48];   
    int cnt;   
  
    Char8ToBit64(plainBlock,plainBits);        
    //初始置换（IP置换） 
    DES_IP_Transform(plainBits);   
    //16轮迭代   
    for(cnt = 0; cnt < ROUND; cnt++){          
        memcpy(copyRight,plainBits+32,32);   
        //将右半部分进行扩展置换，从32位扩展到48位   
        DES_E_Transform(copyRight);   
        //将右半部分与子密钥进行异或操作   
        DES_XOR(copyRight,subKeys[cnt],48);    
        //异或结果进入S盒，输出32位结果   
        DES_SBOX(copyRight);   
        //P置换
        DES_P_Transform(copyRight);   
        //将明文左半部分与右半部分进行异或   
        DES_XOR(plainBits,copyRight,32);   
        if(cnt != ROUND - 1){   
            //最终完成左右部的交换   
            DES_Swap(plainBits,plainBits+32);   
        }   
    }   
    //逆初始置换（IP^1置换）   
    DES_IP_1_Transform(plainBits);   
    Bit64ToChar8(plainBits,cipherBlock);   
    return 0;   
}   
  
//解密单个分组
static int DES_DecryptBlock(ElemType cipherBlock[8], ElemType subKeys[16][48],ElemType plainBlock[8]){   
    ElemType cipherBits[64];   
    ElemType copyRight[48];   
    int cnt;   
  
    Char8ToBit64(cipherBlock,cipherBits);          
    //初始置换（IP置换）   
    DES_IP_Transform(cipherBits);   
       
    //16轮迭代   
    for(cnt = ROUND - 1; cnt >= 0; cnt--){         
        memcpy(copyRight,cipherBits+32,32);   
        //将右半部分进行扩展置换，从32位扩展到48位   
        DES_E_Transform(copyRight);   
        //将右半部分与子密钥进行异或操作   
        DES_XOR(copyRight,subKeys[cnt],48);        
        //异或结果进入S盒，输出32位结果  
        DES_SBOX(copyRight);   
        //P置换   
        DES_P_Transform(copyRight);        
        //将明文左半部分与右半部分进行异或   
        DES_XOR(cipherBits,copyRight,32);   
        if(cnt != 0){   
            //最终完成左右部的交换   
            DES_Swap(cipherBits,cipherBits+32);   
        }   
    }   
    //逆初始置换（IP^1置换）   
    DES_IP_1_Transform(cipherBits);   
    Bit64ToChar8(cipherBits,plainBlock);   
    return 0;   
}   

/*加密数据（字符串）
 *plainBuffer:输入数据
 *keyBuffer:密钥（8字节）
 *cipherBuffer:输出数据
 *n:加密数据长度
 */
int DES_Encrypt(ElemType *plainBuffer, ElemType *keyBuffer, ElemType *cipherBuffer, int n){
    int des_size = n;
    int des_count = 0;
    int count = 0;
    ElemType plainBlock[8],cipherBlock[8],keyBlock[8];
    ElemType bKey[64];   
    ElemType subKeys[16][48];   

    //设置密钥   
    memcpy(keyBlock,keyBuffer,8);
    //将密钥转换为二进制流   
    Char8ToBit64(keyBlock,bKey);   
    //生成子密钥   
    DES_MakeSubKeys(bKey,subKeys); 

    while (des_count + 8 <= des_size){
        memcpy(plainBlock,plainBuffer + des_count,8);
        DES_EncryptBlock(plainBlock,subKeys,cipherBlock);  
        memcpy(cipherBuffer + des_count,cipherBlock,8) ;   
        des_count += 8;
    }

    if((count = des_size - des_count)){
        memcpy(plainBlock,plainBuffer + des_count,count);
        //填充   
        memset(plainBlock + count,'\0',7 - count); 
        //最后一个字符保存包括最后一个字符在内的所填充的字符数量   
        plainBlock[7] = 8 - count;   
        DES_EncryptBlock(plainBlock,subKeys,cipherBlock);   
        memcpy(cipherBuffer + des_count,cipherBlock,8);
    }  
    return DES_OK;
}

/*解密数据（字符串）
 *cipherBuffer:输入数据
 *keyBuffer:密钥（8字节）
 *plainBuffer:输出数据
 *n:解密数据长度
 *返回解密后数据长度
 */
int DES_Decrypt(ElemType *cipherBuffer, ElemType *keyBuffer, ElemType *plainBuffer, int n){
    int des_size = n;
    int des_count = 0;
    int count = 0;
    ElemType plainBlock[8],cipherBlock[8],keyBlock[8];
    ElemType bKey[64];   
    ElemType subKeys[16][48];   

    //设置密钥   
    memcpy(keyBlock,keyBuffer,8);
    //将密钥转换为二进制流  
    Char8ToBit64(keyBlock,bKey);   
    //生成子密钥  
    DES_MakeSubKeys(bKey,subKeys); 

    while(1){   
        memcpy(cipherBlock,cipherBuffer + des_count,8); 
        DES_DecryptBlock(cipherBlock,subKeys,plainBlock);
        if(des_count + 8 < des_size){   
            memcpy(plainBuffer + des_count,plainBlock,8);
            des_count += 8;
        } else {  
            break;   
        }   
    }

    //判断末尾是否被填充
    if(plainBlock[7] < 8){
      for(count = 8 - plainBlock[7]; count < 7; count++){   
        if(plainBlock[count] != '\0'){   
          break;   
        }   
      }   
    } 
    if(count == 7){
      memcpy(plainBuffer + des_count,plainBlock,8 - plainBlock[7]);
      return des_count +8 - plainBlock[7];
    } else {
		memcpy(plainBuffer + des_count,plainBlock,8);
      return des_count +8 ;
    }
    return des_count + 8;
}
  
//加密文件  
int DES_Encrypt_File(char *plainFile, char *keyStr,char *cipherFile){   
    FILE *plain,*cipher,*key;
    ElemType *plainBlock,*cipherBlock,keyBlock[8];    
    long fileLen_in,fileLen_out;
    int count;
    if((plain = fopen(plainFile,"rb")) == NULL){   
        return PLAIN_FILE_OPEN_ERROR;   
    }      
    if((key = fopen(keyStr,"rb")) == NULL){   
        return KEY_FILE_OPEN_ERROR;   
    }     
    if((cipher = fopen(cipherFile,"wb")) == NULL){   
        return CIPHER_FILE_OPEN_ERROR;   
    }
    if((count = fread(keyBlock,sizeof(char),8,key)) == 8){
    }
  
    fseek(plain,0,SEEK_END);//将文件指针置尾      
    fileLen_out = fileLen_in = ftell(plain);//取文件指针当前位置       
    rewind(plain);//将文件指针重指向文件头  

    if (fileLen_in % 8 != 0)
      fileLen_out = (fileLen_in/8+1)*8;
    plainBlock = (ElemType *)malloc(fileLen_out * sizeof(ElemType));
    cipherBlock = (ElemType *)malloc(fileLen_out * sizeof(ElemType));
    fread(plainBlock,sizeof(char),fileLen_in,plain);   

    DES_Encrypt(plainBlock,keyBlock,cipherBlock,fileLen_in); 
    fwrite(cipherBlock,sizeof(char),fileLen_out,cipher);  

    fclose(plain);   
    fclose(cipher); 
    fclose(key);
    free(plainBlock);
    free(cipherBlock);
    return DES_OK;
}
  
//解密文件
int DES_Decrypt_File(char *cipherFile, char *keyStr,char *plainFile){   
FILE *plain,*cipher,*key;
    ElemType *plainBlock,*cipherBlock,keyBlock[8];    
    int count;
    long fileLen_in,fileLen_out;
  
    if((plain = fopen(plainFile,"wb")) == NULL){   
        return PLAIN_FILE_OPEN_ERROR;   
    }      
    if((key = fopen(keyStr,"rb")) == NULL){   
        return KEY_FILE_OPEN_ERROR;   
    }     
    if((cipher = fopen(cipherFile,"rb")) == NULL){   
        return CIPHER_FILE_OPEN_ERROR;   
    }
    if((count = fread(keyBlock,sizeof(char),8,key)) == 8){
    }

    fseek(cipher,0,SEEK_END);//将文件指针置尾      
    fileLen_out = fileLen_in = ftell(cipher);//取文件指针当前位置       
    rewind(cipher);//将文件指针重指向文件头  

    plainBlock = (ElemType *)malloc(fileLen_in * sizeof(ElemType));
    cipherBlock = (ElemType *)malloc(fileLen_in * sizeof(ElemType));
    fread(cipherBlock,sizeof(char),fileLen_in,cipher);   

    count = DES_Decrypt(cipherBlock,keyBlock,plainBlock,fileLen_in);
    fwrite(plainBlock,sizeof(char),count,plain); 

    fclose(plain);   
    fclose(cipher); 
    fclose(key);
    free(plainBlock);
    free(cipherBlock);
    return DES_OK;   
}  

/*3DES加密数据（字符串）
 *对区块使用3个64位密钥进行3次加密，相当于增加了密钥长度
 *plainBuffer:输入数据
 *keyBuffer:密钥（24字节）
 *cipherBuffer:输出数据
 *n:加密数据长度
 */
int D3DES_Encrypt(ElemType *plainBuffer, ElemType *keyBuffer, ElemType *cipherBuffer, int n){
    int des_size = n;
    int des_count = 0;
    int count = 0;
	int i;
    ElemType plainBlock[8],cipherBlock[8],keyBlock[24];
    ElemType bKey[3][64]; 
    ElemType subKeys[3][16][48];

	for (i = 0; i < 3 ; i++)
	{
		//设置密钥   
		memcpy(keyBlock+i*8,keyBuffer+i*8,8);
		//将密钥转换为二进制流   
		Char8ToBit64(keyBlock+i*8,bKey[i]);   
		//生成子密钥   
		DES_MakeSubKeys(bKey[i],subKeys[i]); 
	}

    while (des_count + 8 <= des_size){
        memcpy(plainBlock,plainBuffer + des_count,8);
		for (i = 0; i < 3 ; i++)
		{
			DES_EncryptBlock(plainBlock,subKeys[i],cipherBlock);   
		}
        memcpy(cipherBuffer + des_count,cipherBlock,8) ;  
        des_count += 8;
    }

    if((count = des_size - des_count)){
        memcpy(plainBlock,plainBuffer + des_count,count);
        //填充   
        memset(plainBlock + count,'\0',7 - count); 
        //最后一个字符保存包括最后一个字符在内的所填充的字符数量   
        plainBlock[7] = 8 - count;   
		{
			for (i = 0; i < 3 ; i++)
			{
				DES_EncryptBlock(plainBlock,subKeys[i],cipherBlock);   
			} 
		}
        memcpy(cipherBuffer + des_count,cipherBlock,8);
    }  
    return DES_OK;
}

/*3DES解密数据（字符串）
 *cipherBuffer:输入数据
 *keyBuffer:密钥（24字节）
 *plainBuffer:输出数据
 *n:解密数据长度
 *返回解密后数据长度
 */
int D3DES_Decrypt(ElemType *cipherBuffer, ElemType *keyBuffer, ElemType *plainBuffer, int n){
    int des_size = n;
    int des_count = 0;
    int count = 0;
	int i;
    ElemType plainBlock[8],cipherBlock[8],keyBlock[24];
    ElemType bKey[3][64];   
    ElemType subKeys[3][16][48];   

	for (i = 0; i < 3 ; i++)
	{
		//设置密钥   
		memcpy(keyBlock+i*8,keyBuffer+i*8,8);
		//将密钥转换为二进制流   
		Char8ToBit64(keyBlock+i*8,bKey[i]);   
		//生成子密钥   
		DES_MakeSubKeys(bKey[i],subKeys[i]); 
	}

    while(1){   
        memcpy(cipherBlock,cipherBuffer + des_count,8); 
		for (i = 0; i < 3 ; i++)
		{
			DES_DecryptBlock(cipherBlock,subKeys[i],plainBlock);     
		}
        if(des_count + 8 < des_size){   
            memcpy(plainBuffer + des_count,plainBlock,8); 
            des_count += 8;
        } else {  
            break;   
        }   
    }

    //判断末尾是否被填充
    if(plainBlock[7] < 8){
      for(count = 8 - plainBlock[7]; count < 7; count++){   
        if(plainBlock[count] != '\0'){   
          break;   
        }   
      }   
    } 
    if(count == 7){
      memcpy(plainBuffer + des_count,plainBlock,8 - plainBlock[7]);
      return des_count +8 - plainBlock[7];
    } else {
      memcpy(plainBuffer + des_count,plainBlock,8);
      return des_count +8 ;
    }
    return des_count + 8;
}

//3DES加密文件
int D3DES_Encrypt_File(char *plainFile, char *keyStr,char *cipherFile){   
	FILE *plain,*cipher,*key;
	ElemType *plainBlock,*cipherBlock,keyBlock[24];    
	long fileLen_in,fileLen_out;
	int count;
	if((plain = fopen(plainFile,"rb")) == NULL){   
		return PLAIN_FILE_OPEN_ERROR;   
	}      
	if((key = fopen(keyStr,"rb")) == NULL){   
		return KEY_FILE_OPEN_ERROR;   
	}     
	if((cipher = fopen(cipherFile,"wb")) == NULL){   
		return CIPHER_FILE_OPEN_ERROR;   
	}
	if((count = fread(keyBlock,sizeof(char),24,key)) == 24){
	}

	fseek(plain,0,SEEK_END);//将文件指针置尾      
	fileLen_out = fileLen_in = ftell(plain);//取文件指针当前位置       
	rewind(plain);//将文件指针重指向文件头  

	if (fileLen_in % 8 != 0)
		fileLen_out = (fileLen_in/8+1)*8;
	plainBlock = (ElemType *)malloc(fileLen_out * sizeof(ElemType));
	cipherBlock = (ElemType *)malloc(fileLen_out * sizeof(ElemType));
	fread(plainBlock,sizeof(char),fileLen_in,plain);   

	D3DES_Encrypt(plainBlock,keyBlock,cipherBlock,fileLen_in); 
	fwrite(cipherBlock,sizeof(char),fileLen_out,cipher);  

	fclose(plain);   
	fclose(cipher); 
	fclose(key);
	free(plainBlock);
	free(cipherBlock);
	return DES_OK;
}

//3DES解密文件
int D3DES_Decrypt_File(char *cipherFile, char *keyStr,char *plainFile){   
	FILE *plain,*cipher,*key;
	ElemType *plainBlock,*cipherBlock,keyBlock[24];    
	int count;
	long fileLen_in,fileLen_out;

	if((plain = fopen(plainFile,"wb")) == NULL){   
		return PLAIN_FILE_OPEN_ERROR;   
	}      
	if((key = fopen(keyStr,"rb")) == NULL){   
		return KEY_FILE_OPEN_ERROR;   
	}     
	if((cipher = fopen(cipherFile,"rb")) == NULL){   
		return CIPHER_FILE_OPEN_ERROR;   
	}
	if((count = fread(keyBlock,sizeof(char),24,key)) == 24){
	}

	fseek(cipher,0,SEEK_END);//将文件指针置尾      
	fileLen_out = fileLen_in = ftell(cipher);//取文件指针当前位置       
	rewind(cipher);//将文件指针重指向文件头  

	plainBlock = (ElemType *)malloc(fileLen_in * sizeof(ElemType));
	cipherBlock = (ElemType *)malloc(fileLen_in * sizeof(ElemType));
	fread(cipherBlock,sizeof(char),fileLen_in,cipher);   

	count = D3DES_Decrypt(cipherBlock,keyBlock,plainBlock,fileLen_in);
	fwrite(plainBlock,sizeof(char),count,plain); 

	fclose(plain);   
	fclose(cipher); 
	fclose(key);
	free(plainBlock);
	free(cipherBlock);
	return DES_OK;   
}  